Understanding trophic structure variation in fish assemblages of subtropical shallow lakes: Combined effects of ecosystem size, productivity, and disturbance

The eastern Mediterranean marine ecosystem is undergoing massive modification due to biological invasions, overfishing, habitat deterioration, and climate warming. Our ability to quantify these changes is severely hindered by the lack of an appropriate baseline; most ecological datasets date back a few decades only and show already strong signatures of impact. Surficial death assemblages (DAs) offer an alternative data source that provides baseline information on community structure and composition. In this study, we reconstruct the marine fish fauna of the southern shallow Israeli shelf before the opening of the Suez Canal based on fish otoliths. We quantify the age of the otolith DAs by radiocarbon dating, and describe its taxonomic composition, geographic affinity, and trophic structure. Additionally, we test by radiocarbon dating the hypothesis that Bregmaceros, a presumed Lessepsian invader with continuous presence in the Mediterranean throughout the late Cenozoic, is a relict species. The otolith DA dates back to the mid-Holocene because 75% of the dated otoliths of the native species are older than the opening of the Suez Canal in 1869, suggesting that the DA is a proper baseline for quantifying modern impacts. Consistently, 97% of the otoliths and 88% of the species we collected belong to native Mediterranean species. The native anchovy Engraulis encrasicolus dominates the DAs, although gobiids are the most diverse group (14 species, 28%). The DAs show similar trophic structure to present-day pristine Mediterranean coastal fish assemblages. Two non-indigenous species are recorded here for the first time in the Mediterranean Sea, Amblygobius albimaculatus and Callogobius sp., highlighting the importance of DAs for detecting non-indigenous species. Finally, Bregmaceros otoliths are modern, not supporting the previous hypothesis that the taxon is a Pleistocene relict.

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Potential effects of warming on the trophic structure of shallow lakes in South America: a comparative analysis of subtropical and tropical systems

Hydrobiologia ◽

10.1007/s10750-021-04753-0 ◽

2021 ◽

Author(s):

José Luiz Attayde ◽

Rosemberg F. Menezes ◽

Sarian Kosten ◽

Gissell Lacerot ◽

Erik Jeppesen ◽

...

Keyword(s):

Comparative Analysis ◽

South America ◽

Shallow Lakes ◽

Trophic Structure ◽

Tropical Systems

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Trophic structure of fish assemblages associated with macrophytes in lakes of an abandoned meander on the middle river Purus, brazilian Amazon

Acta Scientiarum Biological Sciences ◽

10.4025/actascibiolsci.v38i1.28973 ◽

2016 ◽

Vol 38 (1) ◽

pp. 37 ◽

Cited By ~ 1

Author(s):

Monik Da Silveira Suçuarana ◽

Lucena Rocha Virgílio ◽

Lisandro Juno Soares Vieira

Keyword(s):

Trophic Structure ◽

Fish Assemblages ◽

Brazilian Amazon

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Trophic ecology of the ichthyofauna of a stretch of the Urucu River (Coari, Amazonas, Brazil)

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x2013000100007 ◽

2013 ◽

Vol 25 (1) ◽

pp. 54-67 ◽

Cited By ~ 2

Author(s):

Igor David da Costa ◽

Carlos Edwar de Carvalho Freitas

Keyword(s):

Trophic Structure ◽

Trophic Ecology ◽

Fish Assemblages ◽

Hydrological Cycle ◽

Taxonomic Diversity ◽

Dry Season ◽

Water Levels ◽

Seasonal Fluctuations ◽

Flood Season ◽

Wide Range

INTRODUCTION: The floodplains of the large Amazonian rivers are very productive as a result of seasonal fluctuations of water levels. This favors the fishes as they are provided with a wide range of habitats and food resources; AIM: In this study, we identified the trophic structure of fish assemblages in the upper river Urucu area (State of Amazonas - Brazil), observing seasonal changes determined by the hydrological cycle; Methods: Samples were collected with the aid of gillnets, during the flood season (April/2008) and the dry season (August/2008) in areas upstream and downstream of ports of the Urucu river within the municipality of Coari, Amazonas, Brazil; RESULTS: 902 individuals of seven orders, 23 families and 82 species were collected. Fishes were more abundant in the dry season than in the flood season, and the piscivores and carnivores (Serrasalumus rhombeus and Osteoglossum bicirrhosum) were the most significant trophic categories in the dry season whereas piscivores and insectivores (Serrasalumus rhombeus, Bryconops alburnoides and Dianema urostriatum) were more abundant in the flood season. The trophic diversity, dominance and evenness were very similar in all sampling periods and show lower values than taxonomic index patterns, except for the trophic dominance in the dry season. Taxonomic diversity and dominance were higher in the flood season if compared to the dry season, but figures were quite uniform and there were no great discrepancies between seasons. CONCLUSION: We found through our studies that the dry and flood seasons work as regulatory factors of abundance of fishes of certain trophic categories in the Urucu river, what can be possibly explained by the availability of resources and the food spectrum of each category.

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Environmental constraints structuring fish assemblages in riffles: evidences from a tropical stream

Neotropical Ichthyology ◽

10.1590/1982-0224-20150185 ◽

2016 ◽

Vol 14 (3) ◽

Cited By ~ 9

Author(s):

Fabrício Barreto Teresa ◽

Luzia Shirlei de Souza ◽

Dianne Michelle Alves da Silva ◽

Hugo de Oliveira Barbosa ◽

Jane Dilvana Lima ◽

...

Keyword(s):

Environmental Variables ◽

Fish Assemblages ◽

Environmental Control ◽

Species Abundance ◽

Dispersal Limitation ◽

Ecological Processes ◽

Structure Variation ◽

Central Brazil ◽

Environmental Variations ◽

Trophic Traits

ABSTRACT Riffles are unique habitats regarding to assemblage structure. However, understanding how these assemblages respond to environmental variations in small spatial extents, as within a stream, is a challenge. We assess whether the quantitative structure and the trophic composition of fish assemblages vary predictably among stream riffles. We predict that the variation of environmental conditions will explain species abundance and trophic composition, with the latter presenting higher predictive power, since species would be filtered according to their traits (e.g. diet). Moreover, we expect that the low among-riffle dispersal limitation within a stream and the strong habitat filtering would result in lower importance of spatial variables in the structure of riffle fish assemblages. We tested these predictions by studying 18 riffles of a stream in the Central Brazil. Environmental variables, but not spatial ones, were the most important in explaining the variation in assemblages structure. Environmental variables explained a greater portion of the trophic structure variation (R2=0.62) than of abundance (R2=0.37), indicating that the variation on the trophic traits at community level are more predictable. These results also indicate that these assemblages are subject to environmental control, highlighting the importance of riffle characteristics in driving ecological processes within streams.

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